Research And Implementation Of Trusted Storage System Based On Blockchain And Smart Contract

Traditional electronic storage cannot guarantee the authenticity and reliability of data because of the overcentralized permissions of the third party.Blockchain storage can rely on chained data structures and distributed consensus mechanisms to achieve decentralized trusted storage.However,the management function blockchain can provide is simple,and the calculation of the consensus mechanism is expensive,resulting in low throughput and long delay.Therefore,how to optimize the data management performance of blockchain storage,and support rich functions of data processing,certificate storage and forensics,has become the focus of blockchain research,development and application.This thesis proposes a trusted storage system base on blockchain and smart contract.After depositing,the data is distributed,non-tamperable,safe and credible,applicable for judicial authentication,auditing and other authorities to obtain or verify data.The role-based access control strategy is analyzed from the account book and smart contract level.Based on this,we implements the user attribute-based access control strategy through the chain logic of smart contract,encapsulates and optimizes the attribute-related interface to ensure that only specific users can execute specific contract logic,enhancing data privacy and security.The transaction logic and business rules of smart contract in Ethereum is analyzing.The method of reducing the cost of blockchian storage is discussed.The original data of different file formats are fingerprinted,and stored in the transaction attribute information in Ethereum,enhancing the reliability of the system.The forensics method based on smart contract is desined.By analyzing the RLP coding rules and MPT conversion principles,the block information including the contract function selector and parameter encoding is decoded to restore the data fingerprint,proving the traceability of the system.Finally,experiment is implemented with the functional test and security test,and the credibility and feasibility of the system is analyzed.Experimental results show that it has the trusted storage based on blockchain and smart contact increases the processing credibility,storage credibility and access credibility,and compared with the blockchain storage,it enrichs data management functions,the transaction response time reduces by an average of 150 milliseconds,the block space reduces by fore times,and improves the efficiency of system.